Russian troops are reportedly on the move in Crimea, reinforcing their positions, according to The Associated Press.

Vladislav Seleznyov, a Crimean-based spokesman for the Ukrainian armed forces, said witnesses had seen amphibious military ships unloading approximately 200 military vehicles in the eastern area of Crimea, according to the AP.

Seleznyov also told the AP that another 60 military trucks with no plate numbers were headed towards the Crimean capital of Simferopol from the eastern city of Feodosia.

On Friday, pro-Russia soldiers attempted to take over a Ukrainian base, according to the AP. In a standoff that lasted hours, masked troops cut power and telephone lines and demanded that the 100 Ukrainian troops swear allegiance to Russia. The Ukrainian soldiers barricaded themselves in one of the buildings and the invading troops left around midnight without firing a shot.

Russian Foreign Minister Sergey Lavrov today called the new government in Kiev "radical nationalists," according to the AP.

"The so-called interim government isn't independent, it depends, to our great regret, on radical nationalists who have seized power with arms," Lavrov said at a news conference.

He said nationalist groups use "intimidation and terror" to control Ukraine.

Earlier this week meetings between Secretary of State John Kerry and Lavrov failed to produce any sort of deal over Ukraine.

Russia Threatens to Stop Gas Exports Over Ukraine

As tensions continue to rise in the Ukraine, some European leaders fear Russia could stop exporting natural gas.

Leaders of four central European countries -- Hungary, Poland, Slovakia and the Czech Republic -- urged the U.S. to boost natural gas production in case Russia cuts off supply to the Ukraine or other parts of Europe, according to the AP.

Russian state gas company Gazprom has increased pressure on the Ukraine's new government to pay its $1.89 billion debt or risk being cut off. Gazprom also said the situation could lead to a similar scenario as in 2009 when the country refused to export gas to parts of Europe due to a price dispute with the Ukraine, according to the AP.

Warning Shots Fired as Military Watchdog Attempted to Enter Crimea

Warning shots were fired Saturday when military observers from the watchdog group Organization for Security and Co-operation in Europe (OSCE) attempted to cross into Crimea.

According to the OSCE's Twitter feed, the shots were fired as the members made their third attempt at entering Crimea in as many days. Soldiers in unmarked uniforms have closed off the border between Crimea and the rest of Ukraine.

No one was injured in the incident today, according to the OSCE.

First Ukrainian Paralympic Medalist Dedicates Her Medal to 'Peace' in Ukraine